This paper conducts a simulation analysis of probability reception in detecting radio signal levels in an indoor environment. Femtocell simulations were performed that considered fourth generation (4G) networks, operating at 2.6 GHz (LTE-4G), and WiMAX, at 3.5 GHz. Two indoor scenarios were chosen for this study and simulated signals with and without and interference. The Padè approximant model was used to calculate the propagation loss and received power probability. Environmental factors such as the number of walls/floors are taken into account in the simulation. Finally, a measurement campaign was carried out to validate the simulated results.